1. Field of the Invention
The present invention relates generally to apparatus for separating flat products from a pile of flat products, and more particularly to an apparatus for separating flat products from a pile of flat products, the apparatus including adjustable needles movable from a closing position to an opening position wherein the adjustable needles support the bottom of a pile of flat products in their closing position.
2. Background Information
In the technology of building books, including booklets, magazines, periodicals, and the like, the use of collating systems is well known. These systems typically have a transporting device on which individual flat products, such as signatures or sheets, are gathered to build a book-block set, which then is finished and bound. Typically, a number of feeders are arranged along the transporting device, each of the hoppers comprising a feeding mechanism for feeding an individual flat product from a pile of signatures onto the transporting device, in order to gradually build up the book-block set or to insert a supplement sheet into a pocket of a pocket feeder or into a newspaper arranged in the pocket. Such feeding mechanisms typically employ a sheet-separating device for separating a sheet or other single flat product from a pile of flat products which is arranged in each hopper. The single flat products are drawn from the pile at its bottom end.
A sheet-separating device of this kind is known, for example, from U.S. Pat. No. 3,988,016. This document describes a high-speed paper inserting apparatus for vacuum gripping member grips the lowermost insert from the stack and carries it to a pair of nip rollers which transport the insert to an opened newspaper. A single sheet requires a different sucker stroke than a 120 page or pre-inserted section. The different sucker motion requirements are due to the way the sheets or sections have to be positioned and controlled for proper singulation. Generally, the bottom of the stack is supported by a platform, a so-called signature table having a recess for allowing a sucker to draw a single product from the lowermost end of the pile of products. When the sucker does not contact the pile of products the pile is supported by a movable hook, as shown in U.S. Pat. No. 4,157,692.
Efforts regarding such systems have led to continuing developments to improve their versatility, practicality and efficiency. One area in particular which has required further improvement is the support of the pile of products during the transition times between openings and closings of the lift hook and sucker.
It is an object of the present invention to provide a sheet-separating device with improved separation of the lowermost product of the pile of products.
The present invention provides an apparatus for separating flat products from a pile of flat products, the apparatus including: a plurality of needles arranged in at least one needle group; a respective needle block associated with each needle group, the associated needles being disposed thereon, the respective needle block being movable from a closing position to an opening position, the associated needles supporting a bottom of a pile of flat products when the respective needle block is in the closing position and in the opening position; and a respective group adjustment device associated with each needle group for adjusting a group position of the respective needle group.
Only first and second needle groups may be provided.
An individual needle adjustment device associated with each of the plurality of needles may be provided for adjusting an individual position of the respective needle. The respective distance each of the plurality of needles protrudes under the bottom of the pile of flat products between the closing position and in the opening position may be a function of the individual position of the respective needle. Each individual needle adjustment device may include a set screw arrangement.
The respective distance each of the plurality of needles protrudes under the bottom of the pile of flat products between the closing position and the opening position may be a function of the group position of respective needle group.
A face plate may be provided, each of at least one of the plurality of needles protruding through the face plate when the associated needle block in the closing position and the opening position.
Each group adjustment device may include a nut and screw arrangement. Each group adjustment device may be remotely controllable.
A lift hook and a suction device may be provided.
The present invention also provides a method for separating flat products from a pile of flat products, the method including: providing a plurality of needles arranged in at least one associated needle group disposed on a respective needle block movable from a closing position to an opening position; moving each of the respective needle blocks between the opening and the closing position so as to support a bottom of a pile of flat products using the associated needles by adjusting a group position of each of the respective needle group using a respective group adjustment device associated with the respective one needle group.
Using the present invention, which employs needles to support the signatures during transition between closing and openings of the lift hook and sucker in a flat product-separation device, a finer control of product-separation operations may be achieved, with improved singulation.